1. For use with a boiler erected from a plurality of sections, each section being formed with at least one heatable fluid passage therein, the passage having at least one opening adapted to register with a mating opening in an adjacent section for fluid communication therebetween,
2. A sectional boiler sealing arrangement according to claim 1, wherein said recess means includes an annular recess formed in adjacent sections around the periphery of the respective fluid passage.
3. A sectional boiler sealing arrangement according to claim 1 wherein said annular deformable seal means includes at least one sealing ring located in a groove formed in each said section,
4. A device according to claim 1 where said rigid means comprises at least one pin member for insertion into sockets formed in adjacent boiler sections.
5. A device according to claim 1, wherein said annular deformable seal means comprises plastic sealant, setable in situ to form the deformable seal means,
6. A device according to claim 1, wherein said rigid means includes abutting rigid pads formed on the adjacent boiler sections, a nipple portion formed on one section and a recessed portion formed upon another section for receiving and preventing relative lateral motion of the protruding nipple portion.
7. For use with a boiler having a plurality of sections, each section being formed for the passage of hot gas thereover, with at least one fluid passage therein, the passage having at least one opening for connection to a mating opening in an adjacent section for fluid communication therebetween, the combination therewith of,
8. For use with a boiler having a plurality of sections, each section being formed for the passage of hot gas thereover, with at least one heatable fluid passage therein, the passage having at least one opening for connection to a mating opening in an adjacent section for fluid communication therebetween, the combination of,
BACKGROUND OF THE INVENTION
This invention relates generally to sectional boilers and more particularly to a sealing arrangement for the passages which allow the flow of fluid between the sections of the boiler.
In previous boiler constructions having multiple sections, cast iron or steel nipples has been employed to sealingly join fluid passages between boiler sections. Such nipples have been installed so that each end of a nipple engages a mating opening in the abutting boiler section. Draw rods or other clamps have been used to draw the boiler sections together, thereby effecting the compression seating of the nipples with the passage openings in the boiler sections. This arrangement generally provided a fluidtight connection between the boiler section opening and the nipple end and has been used extensively in sectional boiler manufacturing. However, serious difficulties are encountered with such arrangement. Erection of the boiler is difficult, since it is necessary to apply as much as 70 to 120 foot-pounds of torque to the draw rods in order to seat the compression nipples. Moreover, it was often necessary to assembly the boiler in the boiler factory because of the difficulties encountered on the job in attempting to align and assemble the boiler sections and interconnecting nipples. Further, misalignment of the nipples or draw lugs on sections did not, from a practical standpoint, permit an easy replacement of the sections for repair once a boiler was erected on the job.
It is therefore, the general aim of this invention to provide an improved fluid passage sealing arrangement for adjacent sections in a sectional boiler and the like which overcomes the foregoing disadvantages and eliminates the need for highly stressed compressive sealing utilizing cast nipples between the water passages of the boiler sections. The improved sealing arrangement is characterized by its ability to form a reliable seal which can be easily and rapidly applied with a minimum of assembly or disassembly efforts.
It is another object of this invention to provide a water passage sealing arrangement which can be assembled or disassembled in the field as well as in the factory. It is a related object to provide an intersectional seal for a boiler which is simple, inexpensive and rugged.
It is yet another object of this invention to provide a resilient water passage sealing arrangement between the sections of a sectional boiler which will allow the boiler to be transported readily, and which will prevent misalignment of the sections occuring during transportation.
It is a further object to provide a seal arrangement which allows assembly of the boiler without highly stressing the boiler assembly bolts used therein, and without necessarily utilizing special tools such as torque wrenches in the assembly.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:
FIG. NO. 1 is an overall perspective view of a sectional boiler having installed therein an embodiment of this invention,
FIG. 2 is a partial exploded view of the corners of typical adjacent sections of the boiler showing the various parts of one embodiment of the invention which are to be installed between the boiler sections,
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2, showing in cross section one embodiment of the novel seal as it is installed between adjacent boiler sections,
FIG. 4 is another sectional view taken along line 3--3 of FIG. 2 showing another embodiment of the novel sealing means,
FIG. 5 is still another sectional view taken along line 3--3 of FIG. 2 showing still another embodiment of the sealing means,
FIG. 6 is still another sectional view taken along line 3--3 of FIG. 2 and showing in section still another embodiment of the invention,
FIG. 7 is yet another sectional view taken along line 3--3 of FIG. 2 and showing in section yet another embodiment of the invention as it is installed in the boiler,
FIG. 8 is yet another sectional view taken along line 3--3 in FIG. 2, and showing still another embodiment of the invention in cross section, the boiler section being shown as only partially drawn together, so as to better illustrate the installation of the invention therebetween, and
FIG. 9 is yet another sectional view taken along line 3--3 of FIG. 2, but without the boiler sections being drawn completely into assembled position .
While the invention will be described in connection with certain preferred embodiments, it will be understood that I do not intend to limit the invention to those embodiments. On the contrary, I intend to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention.
Turning first to FIG. 1, there is shown an exemplary sectional boiler 10 of the type wherein the present invention may be incorporated. Generally such boiler sections 11 are fastened together by mechanical devices such as tie rods 12. The sections 11 are erected and shaped so as to define a fire box 13 located centrally thereof in the lowermost portion. For the purpose of firing the boiler, a forced draft type burner or a natural draft fired burner (not shown) may be mounted in place on the front of the boiler adjacent the fire box 13. Hot flue gases are produced by a flame in the fire box and the flue gases pass through the boiler to the vertical smoke collar or flue gas outlet 14 which serves to lead the gases to the chimney.
For the purpose of generating steam or supply heated water to a hot water system, water is circulated through nipples indicated generally at 16 and through heatable fluid passages 17 formed by coring the casting for each boiler section. For fluid communication therebetween, as may be seen in FIG. 2, each of the sections 11 and 11a are provided with openings 20 to register with mating openings 21 in the adjacent sections.
In accordance with the invention, annular deformable seal means 22 are interposed between the sections 11 and 11a in such a manner as to surround the registering passage openings to prevent the leakage of the fluid flowing between the adjacent sections. As illustrated in FIG. 3 and elsewhere the rigid means 23 comprises an annular ring seatable between the sections in annular recesses 24 and 25 formed or machined in each of the adjoining sections around the periphery of the respective fluid passage. This annular ring may be made of steel or other suitable material which will withstand forced imposed by the drawing up of the boiler tie rods 12, which will withstand the pressures and effects of the passage of hot water or live steam, and which will withstand the corrosive effect of the hot flue gases.
For limiting the amount of axial compression in accordance with the invention, upon the deformable means 22 to a predetermined amount, rigid means 23 are interposed between each of the sections. The rigid means is also arranged and dimensioned for preventing lateral shifting of the adjoining sections 11 and 11a with respect to one another.
In the illustrated forms this annular deformable seal means 22 is an elastomeric seal made from rubber, synthetic rubber compounds such as neoprene, butyl rubber, buna N rubber, butadiene rubber, or various thermoplastic compounds. Any compound which may be formed into a flexible annular seal, which will deform slightly so as to form a positive fluidtight seal between adjacent boiler sections, and which is relatively impervious to hot water or steam, may be used. It is also advantageous if the selected compound is not subject to attack by the corrosive effect of hot flue gases.
It is a feature of the invention that the rigid annular ring acts as a spacer or locater for the seal means 22 when the embodiment of the invention shown in FIG. 3 is employed. The rigid means 23 allows the boiler sections 11 and 11a to be drawn together into the illustrated positions when the boiler tie rods are drawn up. In such position, moderate pressure is applied to the flexible seal means 22, so as to provide a fluidtight seal. Excessive pressure, which can damage the flexible seal means through excessive deformation, is prevented, since the rigid annular ring 23 takes up excessive stresses which might be applied to the seal means 22 without allowing further deformation thereof. It will also be noted that the boiler sections 11 and 11a cannot become misaligned with respect to one another while the rigid ring 23 is seated within the annular recesses 24 and 25. Still further, it will be seen that the rigid annular ring 23 surrounds the flexible seal means 22 so as to protect the seal from direct contact with the hot corrosive flue gases. The seal 22, in turn, prevents the hot water, steam, or other fluid passing between the mating openings 20 and 21 from contacting the rigid ring 23 and perhaps leaking therearound.
An alternate embodiment encompassing the scope of the invention is illustrated in FIG. 4. Here, the annular deformable seal means includes sealing rings 30 and 31 located in respective grooves 32 and 33 formed or machined in each section 11 and 11a. For the purpose of exerting sealing pressure upon the sealing rings 30 and 31, and also to prevent skewing misalignment of the adjacent sections 11 and 11a, the rigid spacing means includes a rigid annular ring 34 located between the seal rings 30 and 31 in each section in such a manner as to abut a portion of the peripheries 35 and 36 of each groove 32 and 33, respectively. To properly axially space the various parts so as to prevent excessive deformation and resultant improper sealing, abutting rigid pads 37 and 38 are formed or machined on the sections 11 and 11a, respectively, adjacent the grooves.
As shown in the embodiment illustrated in FIG. 6, the rigid means comprises an annular ring 40 seatable between the sections 11 and 11a in an annular recess 41 and 42 formed in each said adjoining section around the periphery of the respective fluid passages 20 and 21. For protection against the action of flue gases, the annular deformable means 43 is located inside the rigid annular ring 40.
In yet another embodiment of the invention, in FIG. 5 the rigid means comprises at least one pin member 50. The pin 50 is formed for insertion into sockets 51 and 52 formed in the adjacent boiler sections 11 and 11a respectively. To provide proper alignment and spacing of the sections, other pins may be located elsewhere between the adjacent boiler sections, such as, for example, at the site of other header water passage openings between the same adjacent boiler sections. In this illustration, the flexible sealing means takes the form of an annular seal ring 53, which is seated in the grooves 54 and 55 provided in the adjacent boiler sections.
Still another embodiment included within the invention is shown in FIG. 7, wherein the annular deformable seal means comprises setable plastic sealant 60. This sealant may be poured or formed within recesses 61 and 62 formed in the adjacent boiler sections 11 and 11a, respectively. To form the deformable seal means, and to provide a fluidtight seal, the sealant 60 is introduced and is there allowed to set or form, in situ.
Any thermoplastic material which will adequately withstand the pressures and effects of the fluid within the boiler sections as well as the flue gases passing thereover, may be used. In order to axially space the boiler sections 11 and 11a and to prevent skewing movement therebetween, the rigid means include abutting rigid pads 63 and 64 formed on the adjacent boiler sections 11 and 11a, respectively, and a rigid annular ring 65.
To provide complete reversability of sections and consequent ease of boiler erection, it will be noted that each of the mating faces 11 and 11a in each of the embodiments thus far discussed, are identically formed.
A slightly modified embodiment of the invention is illustrated in FIG. 8. In order to prevent relative motion between the boiler sections 11 and 11a in this embodiment, a nipple portion 70 is formed on one section 11a and a recessed portion 71 is formed upon another section 11 for receiving and preventing relative lateral motion of the protruding nipple portion 70. When drawn together, it will be understood that a relatively continuous contact is made between the adjacent boiler sections. For the purpose of providing the fluidtight seal, the annular flexible seal member 72 is provided. To provide the proper axial spacing of the boiler sections, abutting rigid pad portions 73 and 74 are formed on the adjacent boiler sections.
A somewhat similar version of the embodiment discussed immediately above will be found in FIG. 9.
To provide an added measure of protection from the hot fluids inside the boiler sections and the corrosive flue gases passing thereover, the seal 80 is offset slightly from the general interface of the sections 11 and 11a. It will be understood that the general arrangement of a protruding nipple 81, a recessed portion 82, and abutting rigid pad portions 83 and 84 are also provided, and function as described above to provide a tight boiler seal which can be easily assembled and which is not susceptible to misalignment and leaking.
Although described primarily in connection with and generally intended for use in sectional boilers, it will also be understood that the present invention will also find usefulness when employed in radiators and other heat-exchanging apparatus having sectional members.